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Abstract-In this paper, we address the physical-layer security of two-way (bi-directional) transmissions of two terminals with the help of multiple relay nodes in the presence of an eavesdropper, where each node in the network is only equipped with single antenna. The secrecy sum rate is used as the metric of security, which is the rate difference between the legitimate information exchange between...
In this paper, we develop a distributed space-time coding scheme to cope with both time and frequency asynchronism in two-way relay network (TWRN). The convolutional coding is employed to handle multiple timing errors in the networks. We prove that both the cooperative and the multipath diversities can be achieved by linear receivers, e.g., linear zero-forcing (ZF) or minimum mean square error (MMSE)...
Time asynchronism is a practical issue needs to be addressed for a general distributed two-way relay network, where two terminal nodes exchange information through multiple spatial-separated relay nodes. In this paper, we propose an analog network coding (ANC) scheme for a time asynchronous two-way relay network. In the proposed scheme, each relay node linearly transforms the received mixed asynchronous...
Distributed beamforming is a form of collaborative communication, in which wireless nodes adjust the phases of their transmitted signals so that the signals are combined coherently at the destination. This enhances the received signal power and extends the communication range. In this paper, we propose a transmit beamforming method that does not require any explicit feedback information from the receiver...
In this paper, we propose a distributed angle estimation method for wireless sensor network localization with multipath fading. The multiple antenna system is equipped at the anchor and the angle of departure (AOD) can be estimated individually at each sensor node with single antenna system. Further, we exploit the space diversity to improve the estimation performance by deploying multiple parallel...
Cooperative relay networks are inherently time- and frequency- asynchronous due to their distributed nature. The existence of multiple time and frequency offsets results in a time-varying and frequency-selective equivalent channel between relay nodes and destination node. In this paper, we propose a transceiver scheme to combat both time and frequency offsets for cooperative relay networks. At the...
We consider a two-way relay network consisting of multiple pairs of single-antenna users and multiple distributed single-antenna relays. The two communication peers in each pair of users transmit simultaneously to the relays in the first time slot, and the relays rebroadcast the received sum signal weighted by a complex gain, in the second time slot. For multi-user systems, the signal arriving at...
The opportunistic cooperation schemes, where only the “best” relay is selected to forward the message, are well performed in outage probability but with poor fairness among relays. In this paper, we introduce the concept “outage priority based fairness” (OPF), aiming at improving the fairness appropriately without outage performance deterioration. A novel cooperation scheme is proposed to meet the...
A novel distributed angle estimation method for wireless sensor network localization is proposed in this paper. The anchor emits two linear frequency modulation waves simultaneously using its equipped two antenna elements, while the angle of departure of the emitted waves can be estimated independently at each sensor. The method only relies on radio transceivers and requires no time or carrier frequency...
In cooperative communication systems, due to their distributed nature, multiple carrier frequency offsets (CFOs) may occur and make the channel time-varying, thus most existing space-time codes (STC) to collect diversity gain for the co-located multi-input multi-output (MIMO) systems may not be applied directly. In this paper, we propose a family of distributed space-frequency codes (SFCs) for cooperative...
A novel distributed localization method for wireless sensor networks (WSN) is proposed in this paper. Linear frequency modulation (LFM) waves are emitted from two anchors simultaneously to create an interference field. Through the frequency measurement of local RSSI (Received Signal Strength Indication) signal, the TDoA (Time-Difference-of-Arrival) is estimated independently at each sensor to detect...
Multiple frequency offsets (CFO) in cooperative communications are difficult, if not impossible, to compensate completely at the destination node. The multiple CFO make the channel time-varying, and thus the conventional space-time codes to collect diversity gain for co-located multi-input multi-output (MIMO) systems may not be applied directly. In a previous paper, we proposed a distributed space-frequency...
In cooperative communications, due to the distributed nature, multiple different carrier frequency offsets (CFOs) may be present and make the channel time-varying. It is hard for the receiver to compensate multiple CFOs from multiple relay nodes simultaneously. Thus, the conventional space-time codes to collect cooperative diversity for co-located multi-input multi-output (MIMO) systems may not be...
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